Two-dimensional imaging of charge/discharge by Bragg edge analysis of electrode materials for pulsed neutron-beam transmission spectra of a Li-ion battery

Transmission measurement of a commercial Li-ion battery was performed using the pulsed neutron beam provided by the Japan Spallation Neutron Source. A high position resolution two-dimensional neutron detector recorded the neutrons that went through the battery sample. The transmission spectra for each partitioned area on the battery sample were fitted by a function taking into account the coherent elastic scattering of neutrons on the electrode materials. Using the fitting results, we succeeded in obtaining the charge/discharge images through the quantitative crystal surface densities.